Packages



y 7, 1968 M. J. HERRITTY 3,381,884

PACKAGES Filed April 14, 1966 3/4 FIG. I x

M/CHAEJL JI'HEEE/TTY INVENTOR BY 92m wi TTO/ENEY United States Patent C)3,331,884 PACKAGES Michael John Herritty, Haywards Heath, nearLindfield, England, assignor t Monsanto Chemicals Limited, London,England, a British company Filed Apr. 14, 1966, Ser. No. 542,556 Claimspriority, application Great Britain, June 16, 1965, 25,421/65 2 Claims.(Cl. 229-51) ABSTRACT OF THE DISCLOSURE A package having a closure ofsheet thermoplastic which is folded back on itself to form a line ofweakness for easy opening.

This invention relates to packages, and in particular to a new kind ofpackage that can be readily opened when required.

Thermoplastic sheets, especially biaxially orientated resin sheets, arebecoming increasingly used in such applications as packaging, wheretheir properties have facilitated the introduction of mass productiontechniques. Packages made from thermoplastic sheets are in many casesstrong, light and durable; however, in some instances their strength canbe a disadvantage, since it makes the package difficult to open. A noveltype of package which can readily be opened when required has now beendeveloped.

It is a principal object of the present invention to provide a packagewhich can be readily opened.

It is another object of the present invention to provide a package madeusing thermoplastic sheet which can be readily opened.

It is a further object of the present invention to provide method andmeans to carry out the above objects.

This invention will in part be obvious and will in part appearhereinafter.

The invention comprises a package having a closure made from a sheet ofthermoplastic material of which a portion is folded back upon itselftwice so as to form a lap defining a line of weakness along which thesheet can be torn so as to open the package when required.

FIG. I is a sectional side View of a tray covered by sheet materialhaving a folded overlap.

FIG. II is a top plan view of the tray shown in FIG. I.

FIG. III illustrates a package completely enclosed with sheet materialhaving a folded overlap.

FIG. IV illustrates the use of the present invention in a sachet.

Referring to the drawings and more particularly to FIGS. I and II, apackage which comprises a tray 1, which may be a vacuum formed from aplastic such as polystyrene, having heat-sealed to it a transparent lid2 comprising a sheet material such as biaxially orientated polystyrene,folded in two places 4 and 5 to form a lap 3. The lap is held down atits ends 6 and 7 by the seal in such a manner that a finger can easilybe inserted under it near the middle so as to tear the lid away from thetray.

The invention has been specifically illustrated With reference to a traycontainer having a sealed-on lid, but many other types of package can beprovided with a closure in accordance with the invention. Two furtherexamples are shown in FIGS. III and IV. FIG. III shows in perspective afilm-wrapped container such as is used for biscuits, etc., which isprovided with a lap on all four sides, while FIG. IV shows a sachet ofthe type which is often used to contain shampoo, having a lap across onecorner. The above description and particularly the draw- "ice ings areset forth for the purpose of illustration only and not for the purposeof limitation.

Moreover, the invention has been described with reference to a package,which can be empty or already filled with the substance to be packed,but the invention also includes a part or component (of a package)comprising a sheet of thermoplastic material of which a portion isfolded back upon itself twice so as to form a lap. Thus for example thelap might be part of a lid which is sealed to a container after thelatter has been filled.

Preferably the thermoplastic sheet from which the closure is made is asynthetic resin sheet, particularly a transparent sheet of biaxiallyorientated resin. Other suitable resins are polyolefins such aspolyethylene, or polypropylene; styrene copolymers, for instancestyreneacrylonitrile copolymers; polyacrylates, polymethacrylates,polycarbonates; polyvinyl chloride; and polyethylene terephthalate.Thermoplastic cellulose derivatives such as for example celluloseacetate or cellulose triacetate can be employed if desired.

The thermoplastic sheet is normally relatively thin, for instance havinga thickness of between 0.0002 and 0.010 inch, particularly between0.0005 inch and 0.004 inch. A sheet of thickness 0.001 is oftenconvenient to use.

The folded lap in the closure can be produced by any suitable means. Forinstance, blanks can be cut and then folded separately, or the lap canbe produced mechanically in a roll of the material using web fedequipment either by intermittent folding and creasing across the web, orby continuous folding and creasing by passing through rollers.

Where the closure is sealed to another part of the container the sealcan be effected in a variety of ways, for instance by heat-sealing,impulse-sealing or ultrasonic sealing; or by the use of a solvent or anadhesive. Particularly suitable methods are those described in Britishpatent specifications Nos. 922,388, 14,577/62 and 18,560/ 63. Acounter-part of the latter British patent specification was filed in theUnited States Patent Ofiice on Apr. 20, 1964, and was given Ser. No.361,262.

The present invention serves to extend the use of thermoplastic sheetsto many packaging applications where strength and easy opening of thepackage are important.

It is obvious that many variations may be made in the products andprocesses set forth above without departing from the scope of thisinvention.

What is claimed is:

1. A package comprising a container and a closure for the container madefrom a sheet of thermoplastic material of which a portion is folded backon itself twice to form a lap, said lap being sealed at its edges to thecontainer so that a finger may be inserted under the lap to initiallytear the closure away from the container along the sealed edges of theclosure, the surfaces of the folds of the lap within the sealed edgesbeing substantially free of attachment to each other, said lap withinits sealed edges extending substantially in the plane of the remainderof the sheet material.

2. A package according to claim 1 in which the thermoplastic material isa transparent sheet of biaxially oriented polystyrene.

References Cited UNITED STATES PATENTS 3,166,234 1/1965 Amberg 22 9-S1JOSEPH R. LECLAIR, Primary Examiner.

R. PESHOCK, Assistant Examiner.

